Windows 7 Professional Amazon's simple DB

Mike Culver is showing off Amazon's newest web service call Simple DB that is a lightweight data store in the cloud accessed via a REST web service. The structure uses domains (like tables) that contain attribute and value pairs. You can do some cool stuff like have multiple values for attributes within an item as well as attributes that only apply to particular items. You won't find common element of relational databases such as validation,Windows 7 Professional, referential integrity or the ability to query across domains but it's an interesting start in what's becoming a new trend in data storage by moving things to the cloud. The data is stored on Amazon's very successful S3 service and the costs are very cheap and on demand so you only pay for what you use/store. Structured database storage has yet to really move into the cloud in a compelling service but I think that's going to change in the coming years. Storing your data in the cloud has a lot of implications around reliability, backups, privacy which have a big effect on businesses. What do you think the challenges would be for your customers with having their data stored through a service? <div